A liquid crystal display device includes a liquid crystal panel and a backlight unit that is arranged behind the liquid crystal panel. The backlight unit includes a chassis, a light source and an optical member. The chassis has an opening in a surface on a light exit side. The light source is housed in the chassis. The optical member is arranged so as to cover the opening of the chassis and configured to convert light emitted from the light source into planar light.
The optical member includes a diffuser. The diffuser includes a transparent base member in a predetermined thickness and a large number of diffusing particles are scattered in the base member. Outer edge areas of the diffuser are supported by support portions of the chassis. An area of the diffuser inner than the outer edge areas is supported by a support member mounted to the chassis.
An example of such a support member is disclosed in Patent Document 1. The diffuser is supported by support members. The support members include support pins that protrude toward the diffuser. A tip of each support pin is in a point contact with the area of the diffuser inner than the outer edge areas. The support members and the support pins are in a dispersed arrangement within a surface range of the diffuser.    Patent Document 1: Japanese Unexamined Patent Publication No. 2007-33962